selftests/landlock: Test open() and ftruncate() in multiple scenarios

This test uses multiple fixture variants to exercise a broader set of
scnenarios.

Signed-off-by: Günther Noack <gnoack3000@gmail.com>
Link: https://lore.kernel.org/r/20221018182216.301684-7-gnoack3000@gmail.com
Signed-off-by: Mickaël Salaün <mic@digikod.net>

diff --git a/tools/testing/selftests/landlock/fs_test.c b/tools/testing/selftests/landlock/fs_test.c
index 718543f..308f6f3 100644 (file)
--- a/tools/testing/selftests/landlock/fs_test.c
+++ b/tools/testing/selftests/landlock/fs_test.c
@@ -3446,6 +3446,102 @@ TEST_F_FORK(layout1, ftruncate)
 }
 
 /* clang-format off */
+FIXTURE(ftruncate) {};
+/* clang-format on */
+
+FIXTURE_SETUP(ftruncate)
+{
+       prepare_layout(_metadata);
+       create_file(_metadata, file1_s1d1);
+}
+
+FIXTURE_TEARDOWN(ftruncate)
+{
+       EXPECT_EQ(0, remove_path(file1_s1d1));
+       cleanup_layout(_metadata);
+}
+
+FIXTURE_VARIANT(ftruncate)
+{
+       const __u64 handled;
+       const __u64 permitted;
+       const int expected_open_result;
+       const int expected_ftruncate_result;
+};
+
+/* clang-format off */
+FIXTURE_VARIANT_ADD(ftruncate, w_w) {
+       /* clang-format on */
+       .handled = LANDLOCK_ACCESS_FS_WRITE_FILE,
+       .permitted = LANDLOCK_ACCESS_FS_WRITE_FILE,
+       .expected_open_result = 0,
+       .expected_ftruncate_result = 0,
+};
+
+/* clang-format off */
+FIXTURE_VARIANT_ADD(ftruncate, t_t) {
+       /* clang-format on */
+       .handled = LANDLOCK_ACCESS_FS_TRUNCATE,
+       .permitted = LANDLOCK_ACCESS_FS_TRUNCATE,
+       .expected_open_result = 0,
+       .expected_ftruncate_result = 0,
+};
+
+/* clang-format off */
+FIXTURE_VARIANT_ADD(ftruncate, wt_w) {
+       /* clang-format on */
+       .handled = LANDLOCK_ACCESS_FS_WRITE_FILE | LANDLOCK_ACCESS_FS_TRUNCATE,
+       .permitted = LANDLOCK_ACCESS_FS_WRITE_FILE,
+       .expected_open_result = 0,
+       .expected_ftruncate_result = EACCES,
+};
+
+/* clang-format off */
+FIXTURE_VARIANT_ADD(ftruncate, wt_wt) {
+       /* clang-format on */
+       .handled = LANDLOCK_ACCESS_FS_WRITE_FILE | LANDLOCK_ACCESS_FS_TRUNCATE,
+       .permitted = LANDLOCK_ACCESS_FS_WRITE_FILE |
+                    LANDLOCK_ACCESS_FS_TRUNCATE,
+       .expected_open_result = 0,
+       .expected_ftruncate_result = 0,
+};
+
+/* clang-format off */
+FIXTURE_VARIANT_ADD(ftruncate, wt_t) {
+       /* clang-format on */
+       .handled = LANDLOCK_ACCESS_FS_WRITE_FILE | LANDLOCK_ACCESS_FS_TRUNCATE,
+       .permitted = LANDLOCK_ACCESS_FS_TRUNCATE,
+       .expected_open_result = EACCES,
+};
+
+TEST_F_FORK(ftruncate, open_and_ftruncate)
+{
+       const char *const path = file1_s1d1;
+       const struct rule rules[] = {
+               {
+                       .path = path,
+                       .access = variant->permitted,
+               },
+               {},
+       };
+       int fd, ruleset_fd;
+
+       /* Enable Landlock. */
+       ruleset_fd = create_ruleset(_metadata, variant->handled, rules);
+       ASSERT_LE(0, ruleset_fd);
+       enforce_ruleset(_metadata, ruleset_fd);
+       ASSERT_EQ(0, close(ruleset_fd));
+
+       fd = open(path, O_WRONLY);
+       EXPECT_EQ(variant->expected_open_result, (fd < 0 ? errno : 0));
+       if (fd >= 0) {
+               EXPECT_EQ(variant->expected_ftruncate_result,
+                         test_ftruncate(fd));
+               ASSERT_EQ(0, close(fd));
+       }
+}
+
+/* clang-format off */
 FIXTURE(layout1_bind) {};
 /* clang-format on */